Geodia mesotriaena Lendenfeld, 1910

Common name(s):  Armored ball sponge

Synonyms:  Geodia agassizi, Geodia breviana, Cydonium muelleri
Phylum Porifera
 Class Demospongiae
  Subclass Tetractinomorpha
   Order Choristida
    Family Geodiidae
(Geodia mesotriaena from a sea cave on the Olympic coast, July 2006)
(Photo by: Brooke Reiswig, July 2006)
Description:  This white or dirty beige sponge has a rigid feel (careful--it is FULL of glass spicules, and more spicules protrude from the surface).  It grows as a raised lump or spherical form with a broad attachment to the rock.  The surface is made up of sterrasters (82-110 microns long) which appear like paving stones under a hand lens.  Also contains oxeas from 150-600 microns and from 2-8 mm long, orthotriaenes 1.5 to 8 mm long, with bifurcated rays in some; protriaenes 2-17 mm long, anatrienes 4-23 mm long, oxyasters 11-54 microns long, and oxyspherasters 6-32 microns long.  Total sponge can be up to at least 20 cm diameter.

How to Distinguish from Similar Species: Craniella and Stellata do not look like paving stones under the hand lens. Geodinella robusta is whitish yellow to brown and has monoenes, plagiodeaenes, and strongylospherasters but no orthotriaenes, protriaenes, anatriaenes, oxyasters, oxyspherasters, or strongylasters.

Geographical Range:  Southeast Alaska to southern California

Depth Range:


Biology/Natural History:

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Dichotomous Keys:
  Kozloff 1987, 1996
  Smith and Carlton, 1975

General References:
  Lamb and Hanby, 2005

Scientific Articles:

Web sites:

General Notes and Observations:  Locations, abundances, unusual behaviors:

We have found this species intertidally on the open Olympic coast but not near Rosario.

A few of the types of spicules found in Geodia mesotriaena (photos by Brooke Reiswig 2006)
A set of sterrasters (these make up the solid wall of the sponge).  Sterrasters are microscleres. This is the broken end of an oxea.  Notice that it much larger than the other spicules shown--as evidenced by the tiny oxyspheraster beside it.  Oxeas are megascleres.
Oxyasters, as seen here, have pointed tips which converge to a common center. Oxyspherasters, as seen here, have pointed tips and converge toward a common center, which is composed of a spherical ball.

Protriaene spicules

This micrograph shows large protriaene spicules from another individual.  Photo by Joanna Cowles, July 2009

Authors and Editors of Page:
Dave Cowles (2006):  Created original page.  Edited 2009 DLC